Week - 4 - Crash Box Simulation

AIM

To simulate a crash test simulation of crash box impacting a rigid wall in LS-Dyna and compare the result of having thickness of 1.2mm and 1.5mm.

Create a rigid wall

Giving a initial velocity of 50mph (13.89mm/ms)

• The unit system followed is gm-mm-ms
• Plot the cross-sectional force generated in the middle of the crash box

Software Used:

Procedure

• Importing the file
• Open the given model:
  The given file is opened using File --> Open --> LS-Dyna Keyword file
• checking keyword manager  Side bar>Model and part>keyword manager

Section

• side bar>Model and part> keyword manager>all>SECTION>SHELL

 

Material

• side bar>Model and part> keyword manager>all>MAT>PICEWISE_LINEAR_PLASTICITY

 

Hourglass

• side bar>Model and part> keyword manager>all>HOURGLASS

 

Assigning properties to part 

• side bar>Model and part> keyword manager>model>part

 

Contact

• side bar>Model and part> keyword manager>all>CONTACT>AUTOMATIC_SINGLE_SURFACE

 

Boundary Condition

• Side bar> Create entity> Initial>Velocity>cre>Vx

 

Rigid wall

• Side bar> Create entity> Rigidwall>Cre--Planar--1n+NL
• Created rigid wall 20mm away

 

Control Energy

• side bar>Model and part> keyword manager>all>CONTROL>ENERGY

 

Control Termination

• side bar>Model and part> keyword manager>all>CONTROL>TERMINATION

 

DATA Base

• Side bar> Keyword manager>all>database>cross_section_plane

OUTPUTS

d3plot

• side bar> Keyword manager>all>database>BINARY_D3PLOT

 ASCII

side bar> Keyword manager>all>database>ASCII Option

• GLSTAT
• SLEOUT
• RECFORC
• SECFORC

 

 Model Check

• side bar> Keyword manager>Model>Model check

• Save the file using File --> Save --> Save Keyword as a .k file

Run Simulation

File-RUN LS DYNA

Result

Open the keyword+D3PLOT

Crash box with section 1.2mm:

Crash box with section 1.5mm:

Cross-sectional forces generated:

Acceleration plot of a node:

Maximum directional stress and strain:

Plot of all energies:

Conclusion

This analysis ran succesfully and plotted the 1.2mm thckness and 1.5mm thickness crash box.

The maximum stress induced in crashbox with section 1.5mm is 12.04% more than the crashbox with section 1.5mm